Frozen food carton

ABSTRACT

A frozen food carton is erected out of a single blank to comprise a tray portion having a cover flap hingedly connected thereto. The tray portion comprises front, back and sidewalls attached together by corner gusset folds and a narrow flap hingedly connected to the top edges of the front and side panels. The cover flap, hingedly connected to the back panel and having opening means formed therein, is adhesively secured over the three narrow flaps to form a tightly sealed carton closure.

United States Patent [72] Inventor Thomas W. Foster Palo Alto, Calif. [21] Appl. No. 824,512 [22] Filed May 14,1969 [45] Patented Mar. 30, 1971 [73] Assignee Fibreboard Corporation San Francisco, Calif.

[54] FROZEN FOOD CARTON 12 Claims, 6 Drawing Figs. 52 Lisa .Q 229/31, 229/33, 229/36 [51] Int. Cl 865d 5/22, 865d 5/24 [50] Field of Search 229/31, 37 51, 33, 36

[56] References Cited 1 UNlTED STATES PATENTS 3,003,674 10/1961 Ringler 229/51RC 3,008,626 11/1961 Lawrence 229/311 3,146,934 9/1964 Steiger 229/31 3,301,391 1/1967 Guyer 229/51RC 3,399,820 9/1968 Foster et al. 229/51lS 3,443,354 5/1969 Lindstrom 53/47 Primary Examiner-David M. Bockenek AIt0rney Fryer, Tjensvold, F eix, Phillips, and Lempio ABSTRACT: A frozen food carton is erected out of a single blank to comprise atray portion having a cover flap hingedly connected thereto. The tray portion comprises front, back and sidewalls attached together by corner gusset folds and a narrow flap hingedly connected to the top edges of the front and side panels. The cover flap, hingedly connected to the back panel and having opening means formed therein, is adhesively secured over the three narrow flaps to fonn a tightly sealed carton closure.

Patented March 30, 1971 2 Sheets-Sheet 1 INVENTOR THOMAS W. FOSTER ATTORNEYS Patented March 30, 1971 3,572,576

I 2 Sheets-Sheet 2 FIG. 3

INVENTOR THOMAS W. FOSTER FROZEN FOOD CARTON Frozen food and like cartons require tightly sealed comers to prevent leakage and contamination of the commodity retained therein. The availability of heat sealable adhesives or coatings, such as polyethylene, has encouraged the packaging art to utilize a single structure carton comprising a single blank suitably cut and scored to be erected into carton form. Due to the ever increasing number of frozen food cartons being used, even minor savings in theamount of paperboard utilized for such a carton results in collective savings which are substantial. However, a substantial reductionin paperboard utilized for acarton blank normally results in an erected and sealed carton which is highly prone to leakage.

An object of this invention is to overcome the above briefly described problems by providing an economical one-piece blank formed out of a minimum amount of paperboard. The blank is suitably cut and scored to adapt it for expeditious and economic formation into a tightly sealed and leakproof carton. The blank comprises a bottom panel having front, back, and sidewall panels hingedly connected thereto and adapted toform a tray portion. a

Each pair of adjacent front, back and side panels has aweb secured therebetween adapted to form corner gusset folds when the carton is erected. A cover flap, having dimensions coinciding with those of the bottom panel, is hingedly connected to the back panelwhereas a narrow flap is similarly connected to each of the front and side panels. The carton is closed and sealed by securing the cover flap over the narrow flaps.

Other objects and novel features of this invention will become apparent from the following description and accompanying drawings wherein:

FIG. 1 is an isometric view of an erected carton embodying novel features of this invention therein;

FIG. 2 is a top plan view of a blank utilized for the FIG. 1 carton;

FIG. 3 is a top plan view at least partially showing a plurality of blanks in nesting relationship with respect to each other;

FIG. 4 is a view similar to FIG. 1, but showing the closure flaps of the carton in superimposed relationship prior to final sealing;

FIG. 5 is an enlarged, sectional view taken in the direction of arrows 5-5 in FIG. 4; and

FIG. 6 illustrates an intermediate stage of forming a web into'a gusset fold employed in the FIG; 1 carton.

The carton illustrated in FIG. 1 is formed out of the cut and scored blank illustrated in FIG. 2. The blank is preferably coated on both sides with a barrier coating, such as polyethylene. The blank comprises a rectangular bottom panel 11 having front and back panels 12 and 13 hingedly connected to opposite edges thereof by parallel scorelines 14 and 15, respectively. Side panels 16 and 17 are hingedly connected by parallel'scorelines l8 and 19, respectively, to opposite side edges of the bottom panel. Scorelines l8 and 19 are arranged perpendicular relative to scorelines 14 and 15.

A cove flap or top panel 20, having a length and width substantially the same as those of the bottom panel, is hingedly connected to the top edge of back panel 13 by a scoreline 21, disposed parallel relative to scoreline 15. The top panel has converging pairs of spaced cuts or tear means 22-23 and 24- -25 formed on opposite sides thereof to define a triangularly shaped flap 26 terminating at a free end or tab 27 thereof. semicircular and spaced cutouts 28 and 29. aid in defining the tab which aids in the manual opening of the flap.

The cuts are preferably formed to a limited depth on the opposite sides of the top panel to facilitate expeditious and precise opening of flap 26 on the erectedand closed carton. US. Pat. No. 3,399,820, assigned to the assignee of this application, discloses similar cut arrangements and more fully describes the function thereof. For example, such cuts may be formed only through the barrier coating (eg. polyethylene) to assure very clean tear lines when flap 26 is opened.

Scorelines 14, 15, 18 and 19 further define webs 30, 31, 32 and 33 between each of the four pairs of adjacent front, back and side panels. Each web is adapted to form a gusset fold at one of the cartons corners to assure a tight seal thereat. It should be noted that the pair of gusset folds 31 and 32 are identical whereas the pair of gusset folds 30 and 33 are also identical.

Web 31, for example, comprises a scoreline 34 disposed approximately at a 45 angle relative to each scoreline l5 and I8 and intersects therewith. Scoreline 34 terminates at its other end at the apex of a V-shaped portion 35 which is bounded on each side by similar portions 36 and 37. It should be noted that when the carton is formed (FIG. ll) that the two outer portions are folded into superimposed relationship whereas the midportion is folded in half to provide rear corner seals extending the full height of the back and side panels. The formed gusset folds are preferably adhesively secured to the back panel although they could be secured to the side panels.

Web 30, for example, comprises a straight edge portion 38 preferably disposed approximately at an angle of 45 with respect to scorelines 14 and 18. Such straight edge portion is bounded on its sides by intersecting straight edge portions 39 and 40, disposed perpendicular relative to each other. A scoreline 41 intersects the intersection of perpendicular scorelines I4 and 18 and terminates at its other end intermediate the ends of edge portion 38. As shown in FIG. I, the gusset folds and resulting front corner seals, formed by webs 30 and 33, extend the full height of the front and side panels and are preferably adhesively secured to the front panel.

Referring briefly to FIG. 3, it should be noted that webs 30- --33 are constructed and arranged to nest in a snug manner. In particular, a minimum amount of paperboard, indicated by arrow-shaped cutout portions 42 'and 43, is wasted between the blanks. It should be further noted that the remaining panel and flap portions of the blank are quite small when compared with corresponding structures utilized in conventional carton blanks.

Referring again to FIG. 2, the blank further comprises parallel scorelines 44 and 45 hingedly connecting narrow side closure flaps 46 and 47, respectively, to the top edges of side panels 16 and 17. A scoreline 48, parallel to scoreline l4, hingedly connects a narrow front closure flap 49 to the top edge of the front panel. The narrow flaps have vertical widths substantially less than the vertical widths of each of the front, back and side panels.

A perforated tear line 50 is formed in the latter flap and front panel to provide means defining a tab 51 adapted to be manually removed therefrom when flap 26 is opened to expose the closed cartons contents. Spaced protuberances S2 and 53 aid in permitting flap 49 to be readily folded during carton formation and are aligned with a respective cutout 28 or 29 to provide an increased surface area thereat for sealing purposes.

The substantially erected carton (FIG. 1) thus comprises horizontally disposed bottom panel 11 and vertically disposed and coextensive front, back and side panels l2, I3, 16 and 17, respectively. The five panels form a rectangular tray portion defining a receptacle adapted to retain a commodity therein. After such commodity has been deposited in the carton the 4 carton is closed to adopt it for consumption purposes.

US. Pat. application Ser. No. 799,783, filed on Feb. 17, I969 by Theys et al. for Apparatus and Method for Closing and Sealing Cartons," fully describes a method and apparatus for closing and sealing the FIG. 1 carton.

In particular, side closure flaps 46 and 47 are folded inwardly towards each other and front panel fiap 49 is folded inwardly toward the back panel. It should be noted that the front panel flap is superimposed over substantially small end portions of the side closure flaps 46 and 47.

The top panel is then folded and superimposed over and secured to flaps 46, 47 and 49. As suggested above, the carton is preferably fully coated with a heat scalable adhesive, such as polyethylene, to effect a tight and efficient seal at all superimposed carton surface portions. The closed and sealed carton may be readily opened by depressing tab 51 and by peeling flap 26 rearwardly toward the back panel.

lclaim:

1. A carton formed out of a single blank comprising:

a horizontally disposed bottom panel;

vertically disposed and coextensive front, back and side panels hingedly connected to said bottom panel to form a rectangular tray portion defining a receptacle adapted to retain a commodity therein;

a narrow flap hingedly connected to the top free edge of each of said front and side panels, each of said flaps having a vertical width substantially less than the vertical width of each of said front, back and side panels; and

a rectangular and impervious cover panel hingedly connected to a top, free edge of said back panel and having outer corners defined by three straight intersecting free edges and further having a length and a width substan tially the same as the respective length and width of said bottom panel to be coextensive therewith, said cover panel superimposed over all of said narrow flaps and adhesively secured solely to said narrow flaps to form a tightly sealed carton closure.

2. The invention of claim 1 further comprising tear means formed in said cover panel defining a removable flap thereon terminating at a free end thereof adjacent to said front panel.

3. The invention of claim 2 wherein said tear means comprises two pairs of limited depth cuts formed on opposite sides of said cover panel, said pairs of cuts arranged to converge toward said front panel to define a triangularly shaped flap.

4. The invention of claim 2 further comprising means formed in said front panel and the narrow flap connected thereto defining a removable tab positioned to be secured to the free end of said flap to facilitate opening thereof.

5. The invention of claim 4 further comprising spaced cutouts forrned on the free end of said cover panel to define a tab thereat positioned to be secured to said removable tab.

6. The invention of claim 5 further comprising spaced protuberances formed on a free edge of the narrow flap connected to said front panel and each positioned thereon to be aligned with a respective one of said cutouts to increase the sealing area thereat when said cover panel is adhesively secured to the last-mentioned narrow flap.

7. The invention of claim 1 further comprising a gusset fold connected between each of the four pairs of adjacent front,

back and side panels, each gusset fold connected by a vertically disposed scoreline to one of said panels and being substantially coextensive therewith.

8. The invention of claim 1 wherein the narrow flap connected to said front panel is superimposed over substantially small end portions of the narrow flaps connected to said side panels and secured thereto.

9. A carton blank cut and scored to comprise a rectangular bottom panel,

front, back and side panels hingedly connected to edges of said bottom panel,

a web hingedly connected by scorelines between each of the four pairs of adjacent front, back and side panels, each of said webs having a scoreline formed thereon and approximately disposed at a 45 angle relative to each one of the scorelines hingedly connecting each one of its connecting pair of panels,

a narrow flap hingedly connected to a free edge of each of said front and side panels, each of said flaps having a width substantially less than the width of each of said front, back and side panels, and

a rectangular and impervious cover panel hingedly connected to a free edge of said back panel and having outer corners defined by three straight intersecting free edges and further having a length and width substantially the same as the respective length and width of said bottom panel to be coextensive therewith so that upon erection of said carton said cover panel is superimposed over all of said narrow flaps and adhesively secured solely to said narrow flaps to form a tightly sealed carton closure.

10. The invention of claim 9 further comprising tear means formed in said cover panel defining a triangularly-shaped removable flap thereon arranged to converge toward a free edge of said top panel.

11. The invention of claim 10 further comprising means formed in said front panel and the narrow flap connected thereto defining a removable tab positioned to be secured to a free end of said flap to facilitate opening thereof when said blank is formed into a closed carton.

12. The invention of claim 9 comprising a plurality of said carton blanks arranged in nesting relationship with respect to each other with two blanks each having a side edge of the cover panel thereof abutting a side edge of a narrow flap of the other blank and with webs of the two blanks disposed in nest ing relationship. 

1. A carton formed out of a single blank comprising: a horizontally disposed bottom panel; vertically disposed and coextensive front, back and side panels hingedly connected to said bottom panel to form a rectangular tray portion defining a receptacle adapted to retain a commodity therein; a narrow flap hingedly connected to the top free edge of each of said front and side panels, each of said flaps having a vertical width substantially less than the vertical width of each of said front, back and side panels; and a rectangular and impervious cover panel hingedly connected to a top, free edge of said back panel and having outer corners defined by three straight intersecting free edges and further having a length and a width substantially the same as the respective length and width of said bottom panel to be coextensive therewith, said cover panel superimposed over all of said narrow flaps and adhesively secured solely to said narrow flaps to form a tightly sealed carton closure.
 2. The invention of claim 1 further comprising tear means formed in said cover panel defining a removable flap thereon terminating at a free end thereof adjacent to said front panel.
 3. The invention of claim 2 wherein said tear means comprises two pairs of limited depth cuts formed on opposite sides of said cover panel, said pairs of cuts arranged to converge toward said front panel to define a triangularly shaped flap.
 4. The invention of claim 2 further comprising means formed in said front panel and the narrow flap connected thereto defining a removable tab positioned to be secured to the free end of said flap to facilitate opening thereof.
 5. The invention of claim 4 further comprising spaced cutouts formed on the free end of said cover panel to define a tab thereat positioned to be secured to said removable tab.
 6. The invention of claim 5 further comprising spaced protuberances formed on a free edge of the narrow flap connected to said front panel and each positioned thereon to be aligned with a respective one of said cutouts to increase the sealing area thereat when said cover panel is adhesively secured to the last-mentioned narrow flap.
 7. The invention of claim 1 further comprising a gusset fold connected between each of the four pairs of adjacent front, back and side panels, each gusset fold connected by a vertically disposed Scoreline to one of said panels and being substantially coextensive therewith.
 8. The invention of claim 1 wherein the narrow flap connected to said front panel is superimposed over substantially small end portions of the narrow flaps connected to said side panels and secured thereto.
 9. A carton blank cut and scored to comprise a rectangular bottom panel, front, back and side panels hingedly connected to edges of said bottom panel, a web hingedly connected by scorelines between each of the four pairs of adjacent front, back and side panels, each of said webs having a scoreline formed thereon and approximately disposed at a 45* angle relative to each one of the scorelines hingedly connecting each one of its connecting pair of panels, a narrow flap hingedly connected to a free edge of each of said front and side panels, each of said flaps having a width substantially less than the width of each of said front, back and side panels, and a rectangular and impervious cover panel hingedly connected to a free edge of said back panel and having outer corners defined by three straight intersecting free edges and further having a length and width substantially the same as the respective length and width of said bottom panel to be coextensive therewith so that upon erection of said carton said cover panel is superimposed over all of said narrow flaps and adhesively secured solely to said narrow flaps to form a tightly sealed carton closure.
 10. The invention of claim 9 further comprising tear means formed in said cover panel defining a triangularly-shaped removable flap thereon arranged to converge toward a free edge of said top panel.
 11. The invention of claim 10 further comprising means formed in said front panel and the narrow flap connected thereto defining a removable tab positioned to be secured to a free end of said flap to facilitate opening thereof when said blank is formed into a closed carton.
 12. The invention of claim 9 comprising a plurality of said carton blanks arranged in nesting relationship with respect to each other with two blanks each having a side edge of the cover panel thereof abutting a side edge of a narrow flap of the other blank and with webs of the two blanks disposed in nesting relationship. 